The invention relates to the preparation of emulsions and, more particularly, to a process for preparing such emulsions and mixtures of emulsions wherein gelling of additives such as surfactants is avoided and wherein properties of the emulsion can be tailored to desired requirements.
Viscous hydrocarbons such as natural bitumen are found in significant amounts in Canada, the United States, China, Nigeria and Venezuela. These hydrocarbons typically are liquid having viscosities from 1,000 to 600,000 cP at room temperature. This viscosity, and the relative low reactivity of such materials, make for substantial difficulties in handling. One method for addressing such problems is to make an emulsion in water of such materials thereby reducing viscosity of same and consequently improving properties of the product as a fuel.
Different methods have been proposed for preparing such emulsions, and these emulsions must be stabilized using emulsifiers or surfactants which can be added and/or activated from within the hydrocarbon. Additionally, the emulsion should remain stable upon inclusion of other substances or additives as desired.
It is the primary object of the present invention to provide a process for preparing an emulsion of viscous hydrocarbon in water which produces a stable and useful end product.
Other objects and advantages of the present invention will appear hereinbelow.
In accordance with the present invention, the foregoing objects and advantages have been readily attained.
According to the invention, a process is provided for preparing a hydrocarbon in water emulsion, which process comprises the steps of providing a liquid additive that tends to gel when mixed with water at temperatures less than a gelling temperature TG; providing a stream of water at a temperature TC less than said gelling temperature TG; feeding said stream to a mixer having a mixer inlet so as to impart energy to said stream; adding said liquid additive to said stream downstream of said mixer inlet, whereby said liquid additive mixes with said stream and said energy inhibits gelling of said liquid additives so as to provide a substantially homogeneous solution of said liquid additive in water; and mixing said solution with hydrocarbon in a mixer so as to form a hydrocarbon-in-water emulsion.
The water solution preparation step in accordance with the present invention advantageously avoids the formation of gel without excessive use of heating and cooling.
According to a further embodiment of the invention, a process is also provided which allows for fine tuning the emulsion to have desirable properties.